HEXACTTNELLIDS WITH DISCOCTASTERS. 



58 



Genus STAUEOCALYPTUS, ri. gen. 



Discoctasterophorous Eossellids with pentactin 

 h y p o d e r in a 1 i a , the paratangential rays of which never 

 possess hook - like prongs, but are either smooth or 

 minutely and uniformly rough. 



To this new genus I should refer F. E. Schulze 's Rliahdocalijptus 

 Roeperi and L. M. Lambe's Rh. Döwtingi besides 3 new species to be 

 soon described. 



5. Staurocalyptus Dowlingi (L. M. Lambe). 



With some hesitation I consider certain specimens of Staurocali/p- 

 tus from Sagami Sea as identical with this species first described by 

 Lambe {loc. cit.) from a specimen taken in the Strait of Georgia, Van- 

 couver Island, at a depth of about 40 fathoms. From Sagami Sea, I 

 have several, mostly fragmental specimens obtained at depths of over 

 235 fathoms. On these is based the following description. 



Body subcylindrical or vase-like. It may grow to a considerable 

 size about a foot in diameter. Oscular edge turned upwards or in fully 

 developed state reflected outwards in flaps ; simple and smooth or with 

 more or less needle-like prostals. External surface of smaller speci- 

 mens with a veil produced by the heads of prostal pentactins and 

 also with a number of long diactin prostals standing out in isolated 

 positions. After a certain stage of growth, both of these prostalia 

 pleuralia seem to be lost, except pentactin prostals in positions protected 

 from abrading influences. What constitutes one of the special charac- 

 ters of this species, is the spiny nature of the gastrai surface caused by 

 numerous needle-like (parenchymal) diactins that project their ends 

 beyond the gastrai surface. In the specimens examined by Lambe, 

 these gastrai prostals seem to have been wanting. 



Principal parenchymalia are bow-shaped and in large specimens 

 may measure 38 mm. in length, but their dimension is, as in other 

 species, variable according to the size of individuals. 



Liscoctasters with radius of 72-145/i or more, those deeply situated 



